Pneumatic action for musical instruments.



No. 767,672. PATENTED AUG. 16, 1904. M. S. WRIGHT.

PNEUMATIC ACTION FOR MUSICAL INSTRUMENTS. APPLICATION 3mm JULY 8, 1902.

NO MODEL.

Mi Znsssss. I InL/Emfmr' arri 5 5. ZZ'EJ JZ UNITED STATES Patented August 16, 1904:.

PATENT OFFICE...

PNEUMATIC ACTION FOR MUSICAL INSTRUMENTS.

SPECIFICATION forming part of Letters Patent No. 767,672, dated August 16, 1904.

Application filed July 8, 1902, Serial No. 114,725. (No model.)

To all whom it may concern.-

Be it known that I, MORRIS S. WRIGHT, a citizen of the United States, residing at Worcester, in the county of Worcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in Pneumatic Actions for lllusical Instruments, of which the following is a specification, accompanied by drawings forming a part of the same, in which Figure 1 is a transverse sectional view, and Fig. 2 is a detached side view, of the valvestem and collars carried thereon with the valves shown in central vertical section.

Similar reference-figures refer to similar parts in the different views.

The object of my invention is to provide a pneumatic action for musical instruments in which the variation in air-pressure which causes the action to operate is under such control of the performer that the instrument may be played with the feeling and expression produced by the practiced touch of a trained musician, thereby securinga new result in the operation of pneumatic instruments of this class, which is accomplished according to my invention in the construction illustrated in the accompanying drawings by the use of a vacuum-chamber and a valve mechanism for regulating the passage of air into or out of said chamber, by which the main pneumatics for actuating the keys of the instrument are made immediately responsive to the slightest variations of air-pressure in the vacuum-chamber, rendering possible such delicate variations in the touch of the keys as the performer may desire; and my invention contemplates the accomplishment of these objects by periodically varying the air-pressure within an inclosed chamber relatively to the normal air-pressure, whether such variation is produced by the formation of a vacuum or by an increased airpressure within said chamber.

My invention consists in the novel features of construction and combination of parts, as hereinafter described, and pointed out in the annexed claims.

It is well understood that a variation in the air-pressure in an inclosed chamber relatively to the normal air-pressure by which the main pneumatics are actuated may be produced in instruments of this class by an increase of airpressure in the inclosed chamber as well as by a vacuum or partial vacuum, and a change in the valve construction and operation from one system to the other will be well understood by those conversant with this class of instrumentsand within the scope of an ordinary mechanic to accomplish. Therefore I have deemed it necessary to illustrate in the accompanying drawings only that form of mechanism which produces a variation in the airpressure by the exhaustion of air from a vacuum-chamber.

In the construction shown, 1 denotes a por tion of the framework.

2 is the vacuum-chamber.

3 is the pipe which leads to the bellows (not shown) for exhausting the air from the vacuum-chamber.

4: is what is termed the primary pneumatic, the movement of which is controlled by the unequal air-pressure upon its two sides.

5 is the air-supply pipe leading from the tracker-board 6 to the pneumatic, and 7 illustrates the perforated paper which is carried by the usual rolls 8 and 9 over the trackerboard.

10 illustrates what is termed the valvechamber, and this is provided with an opening 11 into the vacuum-chamber 2 and an opening 12 to the outside air. These openings may be arranged as most convenient, and in the present exemplification they are located in alinement one above the other in the top and bottom, respectively, of the valve-chamber 10. The main pneumatic 13 is in open communication with the valve chamber through an orifice 1 k, and arod 15, extending from the main pneumatic, is connected with the mechanism (not shown) for striking the keys of the instrument to be played.

The highest efficiency of my present invention is dependent on the control of air-passages 11 and 12, and the desideratum is to insure the closure of the opening 12 to the outside air in advance of the opening of the passage 11 into the vacuum-chamber on the principle that in the creation of a vacuum in the valve-chamber it is necessary that the introduction of air into the valve-chamber ceases as a preliminary to the exhaust of air therefrom, so that the operation of the main pneumatic, and consequently the playing of the instrument, responds instantly to the disturbance of air equilibrium, resulting in the immediate application of power coincident with the change in air-pressure. This is attained in the present instance by a valve mechanism, as hereinafter described and illustrated in the accompanying drawings, although variations in the same are possible without departing from the scope of my present invention.

A stem 17 is screwed'at its lower end into a socket 23, which has a disk 24 on its lower end resting loosely upon the diaphragm 25 of the primary pneumatic. The valve-stem is guided at its upper and lower ends, respectively, in the frame 18 and 26. On the valvestem 17 three collars 22, 27 and 28 are secured, and the collar 27 is provided with a hub 29, which extends in an upward direction, and the relative distances between the collars 22 and 27 and the collar 28 and the upper end of the hub 29 are precisely the same. The valves 19 and 20 are loosely mounted on the stem between the collars, so that an equal amount of play is afforded for each valve, and a spiral spring 30 is interposed between the collar 27 and the upper valve 19, which normally holds said valve 19 yieldingly against the upper collar 28.

The operation of the mechanism illustrated in the accompanying drawings is as follows: Air is exhausted from the vacuum-chamber by a treadle-operated bellows (not shown) in the usual manner in instruments of this class. When an opening in the perforated paper 7 passes over the tracker-board, air rushes through the pipe 5 beneath the diaphragm 25 of the primary pneumatic, thereby raising the valve-stem 17 and its attached collars 22, 27 and 28. The valve 19 is held against the collar 28 by the spring 30 carrying the hub 29 against the valve 19 and raising the collar 28 above the valve. During this upward movement of the valve-stem the collar 22 strikes the valve 20 to open the opening 11 simultaneously with the closing ofthe opening 12, the valve 20 being held on its valve-seat by gravity until it is lifted by the collar 22. In this position of the valves the opening 12 is closed and the opening 11 is opened, and the air contained in the valve-chamber 10 and main pneumatic 13 rushes into the vacuum-chamber 2, producing a partial vacuum within the main pneumatic, which is collapsed by the pressure of the outside air and through the rod 15 operating the key-striker. Meanwhile the imperforate portion of the paper 7 has closed the opening in the tracker-board, and the air contained in the pipe 5 exhausts through a vent-opening 31 into the vacuum-chamber 2. The valve-stem l7 and connected collars 22, 27, and 29 then descend by gravity; but the valve 19 is held against its valve-seat by the pressure of the spring 30 until by the continued movement of the valve-stem the valve is struck by the collar 28, when both move down together, allowing air to flow through the opening 12 into the chamber 10. Prior to or simultaneouly with the contact of the collar 28 and valve 19 the collar 22 has passed below the plane of the valve-seat of the valve 20, allowing the latter to descend and close the opening 11. The valve 20 will descend by gravity, as the support of the collar 22 is removed, and its descent is likewise facilitated by the downward movement of air from the chamber 10 into the vacuum-chamber 2, closing the passage between the chamber 10 and the chamber 2, while the downward movement of the valve 19 admits air to the chamber 10, refilling the pneumatic 13. The action of the main pneumatic is therefore produced by the variation of air equilibrium, and by my present invention these changes in air-pressure are sharply defined and may be varied with great rapidity by the action of the bellows, permitting a perfect modulation of tones as contradistinguished from sudden and violent strokes so common heretofore in instruments of this character, and thereby insuring greater sensitiveness of the pneumatics in response to the movement of the bellows and materially reducing the volume of air to be exhausted from the vacuum-chamber, requiring less movement and securing greater ease in the operation of the bellows.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a pneumatic action for musical instruments, comprising an inclosed chamber provided with outlet and inlet openings in alinement for the passage of air, the combination with said openings of a Valve-stem passing through said openings, a pair of valves inclosed in said chamber and held loosely on said stem, a spring applied to one of said valves to allow said valve to yield on the valve-stem and fixed collars attached to said valve-stem, and arranged to engage said valves to open and close said openings, substantially as described.

2. In a pneumatic action for musical instruments, an inclosed chamber having outlet and inlet openings in alinement, a valve-stem passing through said openings, valves held loosely on said valve-stem, fixed collars attached to said stem and arranged to engage said valves to open and close said openings, and a spring acting against one of said valves and one of said collars to allow a slight yielding movement to said valve relatively to said collar, substantially as described.

3. In a pneumatic action for musical instruments, the combination with an inclosed chamber having outlet and inlet openings for the passage of air, of a valve-stem, a pair of valves held loosely on said stem, collars attached to said stem outside said valves, a collar attached to said stem between said valves and a spring between said intermediate collar and one of said Valves, to permit a slight yielding movement to said valve, substantially as described.

4. In a pneumatic action for musical instruments, comprising an inclosed chamber having an inlet-opening in its upper wall communicating with the outside air and an outletopening in its lower wall leading to a vacuum-chamber, a valve-stem passing through said openings, valves held loosely on said stem to close said openings, collars attached to said stem to move said valves, and a spring interposed between one of said collars and the valve closing said inlet-opening, whereby said valve is allowed a slight yielding movement, substantially as described.

5. In a pneumatic action for musical instruments, the combination with an inclosed airchamber having an inlet-opening in its upper wall and an outlet-opening in its lower wall, a vacuum-chamber communicating with said outlet-opening, an upright valve-stem passing through said openings, valves held loosely on said stem to close said openings, collars attached to said valve-stems at different distances from said valves when said valve-stem is in its lowest position, whereby they will engage said valves at difierent periods in the movement of the valve stem to close said valves, and a spring applied to one of said valves to permit a yielding movement of said valve, substantially as described.

6. In a pneumatic action for musical instruments, the combination with an inclosed chamher having inlet and outlet openings in its upper and lower walls respectively with said openings in alincment, a reciprocating valvestem passing through said openings, a pair of valves'held loosely on said stem and between the upper and lower walls of said chamber, collars attached to said stem to move said valves, and a spring carried by said valvestem with its tension applied to the upper of said valves, substantially as described.

7. In a pneumatic action for musical instruments comprising an inclosed chamber having an inlet and an outlet opening, the combination with said openings of avalve-stem, valves loosely held on said stem to close said openings, collars attached to said valve-stem above and below said valves, a collar attached to said valve-stem between said valves, a spring interposed between said collar and the upper valve, and a hub on said interposed collar arranged to be brought into contact with the upper valve when closed, substantially as described.

Dated this 3d day of July, 1902.

MORRIS S. WRIGHT.

Witnesses M. M. SOHUERMANN, RUFUS B. FOWLER. 

